In the absence of a ready source of drinking water, it is common for people to carry bottles or other receptacles containing potable water. Bottles are pre-filled in order that the person should have access to safe drinking water.
However, this approach presents a number of problems. It is difficult and often impossible to guarantee the quality of the water they are using to fill their bottle. The person has to make a calculation of the time they will be away from the nearest source of drinking water and carry an appropriate amount of water with them for their journey. The amount of water that the person can carry is finite. However, the amount of water required is susceptible to both delays in their journey and changes in conditions (for example, the weather gets hotter they will consume more water). In extreme conditions this lack of access to potable water can lead to death.
Furthermore, if the person chooses to drink the water from the surrounding environment they run the risk of becoming poisoned by chemicals or struck down by disease through the ingestion of bacteria or viruses living naturally in the water. Additionally if the person only had access to saltwater the consequences of drinking this are severe. Drinking seawater leads to dehydration which leads to seizures, unconsciousness, and brain damage. In extreme circumstance the kidneys become overwhelmed and shut down. This leads to death.
The use of sanitising tablets (chemical disinfectant) is one current method of killing bacteria and viruses in the water. However, it does not remove hazardous chemicals. Furthermore, even if precise instructions for use are followed a risk still remains that the bacteria or viruses are not killed. This is because they often reside within particulate matter suspended in the water which the disinfectant is unable to penetrate. This method therefore cannot be successfully relied upon to protect the user and leaves them susceptible to illness and or death. Furthermore these disinfectant chemicals remain in the water leaving a foul and unpleasant residual taste in the mouth of the user. Additionally, some people have an intolerance to these chemical disinfectants.
Another current method of water purification is to use a portable rudimentary filter. However, while some portable devices are able to remove bacteria to an acceptably safe level, they are unable to remove viruses because the pore size of the filter is simply too large. The pore size in a filter is the diameter of the holes through which the material to be filtered is passed. They are also unable to remove chemicals to an acceptable level. Moreover they are unable to desalinate the water.
All of the current methods for carrying or purifying water are unsatisfactory as they do not provide adequate filtration to ensure water is safe for consumption.
Another difficulty that has been found in the field of conventional liquid carriers is that it is typically necessary to hold the carrier in a particular orientation if liquid is to be dispensed. This can make the carriers awkward to use in various circumstances.